Not able to view the forum Topics in WPMU DEV forum

I have created a forum from admin panel and copy and paste the shortcode for that forum in page editor.

But when I want to view created topics while clicking the "Title of topic" then page redirected to the "404".

However I have tried to resolve this issue by changed the permalinks option but no luck.

Page Url :

http://homeownerspace.com/forum-testing/